Field of the Invention
The present invention relates to a testing device and a testing unit of an engine.
Description of the Related Art
A device for conducting a test without combustion of fuel is proposed as a testing device of an engine. Japanese Patent No. 4315957, for example, discloses a device for measuring pressure fluctuation of an intake port or an exhaust port by rotating a crank shaft by an electric motor.
A unit for measuring pressure fluctuation of the intake port and the exhaust port is generally provided with a pipeline connected to the ports, a sensor for detecting a pressure inside the pipeline, and a pipeline valve for opening/closing the pipeline. As a test example, there is a test for checking whether or not responsiveness of the intake/exhaust valve is within a reference value in an overlap zone of the intake/exhaust valve, for example. In this case, a pipeline on an intake side is opened, while the pipeline on the exhaust side is closed, and pressure fluctuation on the intake side is measured. To the contrary, a pipeline on the exhaust side is opened, while the pipeline on the intake side is closed, and pressure fluctuation on the exhaust side is measured.
From the viewpoint of measurement accuracy of pressure fluctuation, a capacity inside the pipeline from the port to the pipeline valve is preferably small. If the capacity in the pipeline is large, responsiveness of pressure fluctuation lowers. Thus, a pipeline length from the port to the pipeline valve is preferably small.
On the other hand, a valve with actuator such as an air cylinder is used as the pipeline valve in terms of automation of opening/closing of the valve through automatic control. However, the valve with actuator requires an arrangement space for an actuator and has limitation in reduction of the pipeline length.